Messages in this thread Patch in this message | | | Subject | [PATCH 23 of 31] x86: unify pgd ctor/dtor | Date | Mon, 17 Mar 2008 16:37:14 -0700 | From | Jeremy Fitzhardinge <> |
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All pagetables need fundamentally the same setup and destruction, so just use the same code for everything.
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com> Cc: Andi Kleen <ak@suse.de> --- arch/x86/mm/pgtable.c | 59 +++++++++--------------------------------- include/asm-x86/pgtable.h | 16 +++++++++++ include/asm-x86/pgtable_32.h | 15 ---------- include/asm-x86/pgtable_64.h | 2 - 4 files changed, 30 insertions(+), 62 deletions(-)
diff --git a/arch/x86/mm/pgtable.c b/arch/x86/mm/pgtable.c --- a/arch/x86/mm/pgtable.c +++ b/arch/x86/mm/pgtable.c @@ -59,50 +59,6 @@ list_del(&page->lru); } -#ifdef CONFIG_X86_64 -pgd_t *pgd_alloc(struct mm_struct *mm) -{ - unsigned boundary; - pgd_t *pgd = (pgd_t *)__get_free_page(GFP_KERNEL|__GFP_REPEAT); - unsigned long flags; - if (!pgd) - return NULL; - spin_lock_irqsave(&pgd_lock, flags); - pgd_list_add(pgd); - spin_unlock_irqrestore(&pgd_lock, flags); - /* - * Copy kernel pointers in from init. - * Could keep a freelist or slab cache of those because the kernel - * part never changes. - */ - boundary = pgd_index(__PAGE_OFFSET); - memset(pgd, 0, boundary * sizeof(pgd_t)); - memcpy(pgd + boundary, - init_level4_pgt + boundary, - (PTRS_PER_PGD - boundary) * sizeof(pgd_t)); - return pgd; -} - -void pgd_free(struct mm_struct *mm, pgd_t *pgd) -{ - unsigned long flags; - BUG_ON((unsigned long)pgd & (PAGE_SIZE-1)); - spin_lock_irqsave(&pgd_lock, flags); - pgd_list_del(pgd); - spin_unlock_irqrestore(&pgd_lock, flags); - free_page((unsigned long)pgd); -} -#else -/* - * List of all pgd's needed for non-PAE so it can invalidate entries - * in both cached and uncached pgd's; not needed for PAE since the - * kernel pmd is shared. If PAE were not to share the pmd a similar - * tactic would be needed. This is essentially codepath-based locking - * against pageattr.c; it is the unique case in which a valid change - * of kernel pagetables can't be lazily synchronized by vmalloc faults. - * vmalloc faults work because attached pagetables are never freed. - * -- wli - */ #define UNSHARED_PTRS_PER_PGD \ (SHARED_KERNEL_PMD ? KERNEL_PGD_BOUNDARY : PTRS_PER_PGD) @@ -120,7 +76,8 @@ ptes in non-PAE, or shared PMD in PAE), then just copy the references from swapper_pg_dir. */ if (PAGETABLE_LEVELS == 2 || - (PAGETABLE_LEVELS == 3 && SHARED_KERNEL_PMD)) { + (PAGETABLE_LEVELS == 3 && SHARED_KERNEL_PMD) || + PAGETABLE_LEVELS == 4) { clone_pgd_range(pgd + KERNEL_PGD_BOUNDARY, swapper_pg_dir + KERNEL_PGD_BOUNDARY, KERNEL_PGD_PTRS); @@ -148,6 +105,17 @@ pgd_list_del(pgd); spin_unlock_irqrestore(&pgd_lock, flags); } + +/* + * List of all pgd's needed for non-PAE so it can invalidate entries + * in both cached and uncached pgd's; not needed for PAE since the + * kernel pmd is shared. If PAE were not to share the pmd a similar + * tactic would be needed. This is essentially codepath-based locking + * against pageattr.c; it is the unique case in which a valid change + * of kernel pagetables can't be lazily synchronized by vmalloc faults. + * vmalloc faults work because attached pagetables are never freed. + * -- wli + */ #ifdef CONFIG_X86_PAE /* @@ -246,7 +214,6 @@ pgd_dtor(pgd); free_page((unsigned long)pgd); } -#endif int ptep_set_access_flags(struct vm_area_struct *vma, unsigned long address, pte_t *ptep, diff --git a/include/asm-x86/pgtable.h b/include/asm-x86/pgtable.h --- a/include/asm-x86/pgtable.h +++ b/include/asm-x86/pgtable.h @@ -344,6 +344,22 @@ pte_update(mm, addr, ptep); } +/* + * clone_pgd_range(pgd_t *dst, pgd_t *src, int count); + * + * dst - pointer to pgd range anwhere on a pgd page + * src - "" + * count - the number of pgds to copy. + * + * dst and src can be on the same page, but the range must not overlap, + * and must not cross a page boundary. + */ +static inline void clone_pgd_range(pgd_t *dst, pgd_t *src, int count) +{ + memcpy(dst, src, count * sizeof(pgd_t)); +} + + #include <asm-generic/pgtable.h> #endif /* __ASSEMBLY__ */ diff --git a/include/asm-x86/pgtable_32.h b/include/asm-x86/pgtable_32.h --- a/include/asm-x86/pgtable_32.h +++ b/include/asm-x86/pgtable_32.h @@ -104,21 +104,6 @@ #else # include <asm/pgtable-2level.h> #endif - -/* - * clone_pgd_range(pgd_t *dst, pgd_t *src, int count); - * - * dst - pointer to pgd range anwhere on a pgd page - * src - "" - * count - the number of pgds to copy. - * - * dst and src can be on the same page, but the range must not overlap, - * and must not cross a page boundary. - */ -static inline void clone_pgd_range(pgd_t *dst, pgd_t *src, int count) -{ - memcpy(dst, src, count * sizeof(pgd_t)); -} /* * Macro to mark a page protection value as "uncacheable". On processors which do not support diff --git a/include/asm-x86/pgtable_64.h b/include/asm-x86/pgtable_64.h --- a/include/asm-x86/pgtable_64.h +++ b/include/asm-x86/pgtable_64.h @@ -24,7 +24,7 @@ #endif /* !__ASSEMBLY__ */ -#define SHARED_KERNEL_PMD 1 +#define SHARED_KERNEL_PMD 0 /* * PGDIR_SHIFT determines what a top-level page table entry can map
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